Amorphous thermoplastics have been used for some considerable time in hotmelt adhesives. Hotmelt adhesives of this kind, however, exhibit very poor retention of their three-dimensional shape; in other words, the shape dictated on application has within a very short time, as a result of flow of the adhesive, undergone such significant change that the geometry of the adhesive is for many applications no longer acceptable.
Polyurethane polymers terminated with aldimine groups are proposed by WO 2008/052999 A1, in combination with a liquid polyurethane polymer, for use in hotmelt adhesives for the purpose of influencing the open time and early strength.